MIDDLEBURY, Vermont (AP) -- A group of college students has set out on a post-finals cross-country road trip that is going to smell a lot like french fries.

But at least there won't be any squabbles over gas money: Their converted school bus is fueled by used vegetable oil from cafeterias and fast-food restaurants.

The 13 Middlebury College students said they wanted to combine their rite-of-passage road trip with an environmental message.

Vegetable oil creates less pollution than diesel fuel, said Thomas Hand, 19, who took a crash course at Middlebury in converting diesel tractor engines to run on vegetable oil.

"It's an energy source that comes from the United States. It's being self-sufficient," Hand said. "Also, it's free. It's using some resource that was going to be thrown away and reusing it."

The students are not the first to power their wheels with vegetable oil. Activist Joshua Tickell drove about 25,000 miles on his "Veggie Van USA" tours in the late 1990s.

The Middlebury students left campus Monday night and plan to arrive in Conway, Washington, by June 11, with plenty of stops in between to drop off classmates and do some rock climbing.

Along the way, they will be keeping an eye out for restaurants to get them there. Based on a few trial runs in Vermont, the students -- several of whom are environmental studies majors -- are optimistic they will find the fuel they need.

The students filter the vegetable oil and store it in two vats on the bus. To get the bus rolling, the students first start it briefly with diesel fuel to heat and lower the viscosity of the vegetable oil.

They are sure to draw attention: They will be cruising no faster than 55 mph, with "Powered by Veggie Oil" painted on the back of the bus. And the oil "smells a little bit like whatever it was used to fry -- sometimes you get onion rings, french fries, chicken patties," Hand said.

The students plan to keep people posted through journal entries and photographs on the Internet.

"It's part of an adventure we'll remember for the rest of our lives hopefully," said Logan Duran.

These Democrats up in Texas  they may not be patriots, but they did stay at a Holiday Inn Express last night.-Rep. Tom DeLay on the "fugitive" Texas Democrats

Just the other day I was driving past a VW with "powered by vegetable oil" in black letters all over it. It also had the number 32 on the back, if anyone happens to know the driver. I can't imagine there's too many VW's around like that. I think that if I was stuck behind that bus, smelling their exhaust, I'd probably get pretty hungry. They say they are environmentalists, but maybe they are being secretly financed by the fast food industry, who just happens to have a Micky D's or Burger King along every major road. Think about it!

'But if one is struck by me only a little, that is far different, the stroke is a sharp thing and suddenly lays him lifeless, and that man's wife goes with cheeks torn in lamentation, and his children are fatherless, while he, staining the soil with his red blood, rots away, and there are more birds than women swarming about him.' Diomedes, The Iliad of Homer